1. Field of the Invention
The present invention relates to fixing structure and method of fixing an upper cup muffler, and more particularly to fixing structure and method of fixing an upper cup muffler covering a discharge valve provided to an upper bearing portion for sealing the opening of an upper cylinder in a hermetically sealed compressor that is equipped with an electrically-driven element provided at the upper portion of a hermetically sealed container and a rotationally compressing element driven by the rotating shaft of the electrically-driven element and provided at the lower portion of the hermetically sealed container, the electrically-driven element having an oil pool in which oil is stocked at the bottom portion, and the rotationally compressing element having the upper cylinder and a lower cylinder.
2. Description of the Related Art
A hermetically sealed compressor equipped with an electrically-driven element at the upper portion of a hermetically sealed container and a rotationally compressing element at the lower portion of the hermetically sealed container has been disclosed in JP-A-10-103223, for example, and has been broadly known. In this hermetically sealed compressor, the hermetically sealed container has an oil pool in which oil is stocked at the bottom portion, and the rotationally compressing element is driven by the rotating shaft of the electrically-driven element and equipped with an upper cylinder and a lower cylinder.
In the hermetically sealed compressor thus constructed, large noise occurs due to pressure pulsation of refrigerant compressed in the cylinder when it is discharged from the cylinder into the hermetically sealed container. Under such a situation, a cup muffler is used to suppress the noise caused by the pressure pulsation of the compressed refrigerant, a cup muffler has been used. The cut muffler is disclosed in detail in JP-A-05-133376 and JP-A-06-159281, for example.
In order to fix a cup muffler (upper cup muffler) to an upper bearing portion for sealing the opening of the upper cylinder, it is general that the upper cup muffler is pressed and engagedly fitted in the upper bearing portion so that the lower end peripheral side surface of the upper cup muffler is brought into planar contact with the outer side surface of the upper bearing portion.
However, according to the method of fixing the upper cup muffler to the upper bearing portion by pressing and engagedly fitting the upper cup muffler in the upper bearing portion, when a new type of hermetically sealed compressor is developed by changing the shape of the upper bearing portion of the old type of hermetically sealed compressor described above in some degree, the same upper cup muffler as the old type cannot be fixed to the new type, and thus the upper cup muffler for the new type of hermetically sealed compressor must be developed in connection with the change of the upper bearing portion of the new type of hermetically sealed compressor.